Hi grl.
I found this Kawasaki HA045D-AT25 Demo (Specific model reference) for Sale, and if it's still available, may be a direct replacement the one stolen....
http://www.machines4u.com.au/view/advert/Demo-Kawasaki-Brushcutter-Christmas-Bargain-/268329/Judging by my search results, it seems this machine is actually a KBH45B.
Also found a .pdf on the link below showing your KBH45B specifications to allow comparisons to other machines:-
http://www.cuttingedgeequipment.com.au/kawasaki.htmlHope this helps.